Re: Need: list of Unicode characters that have canonical decompositions.

Karl Williamson wrote:

 > I'm presuming you need this not for a one-time only thing, but to be
 >  able to run this program over and over.

Yes -- this is for a module that will be usable in a number of 
situations. See 
http://search.cpan.org/~bhallissy/Text-Unicode-Equivalents-0.05/.

The current implementation cheats by accessing unicore/Decomposition.pl 
exactly the same way Unicode::UCD does.

 > You can always download UnicodeData.txt from the Unicode web site.

Yes I can -- and certainly have done for my personal use. But including 
that file (or some derivative) in a general purpose module would mean 
that it wouldn't necessarily have the same Unicode version as the Perl 
installation into which my module might be installed. And besides, the 
information I need is already in the Perl core -- though supposedly not 
usable.

 > In a regular expression,
 > \p{Dt= can} (Decomposition_Type=Canonical) will match all characters
 >  that you want.

Yes, I understand that I can test a character to see if it has a 
particular decomposition, but I'm not sure I understand how to use a 
regex to generate a complete list of characters with decompositions.

 > I'm thinking that 5.16 will have the stringification
 > of that regex include the list you want, but not in 5.14, and
 > stringification is not necessarily fixed either.
 >
 > I could easily write a new function for UCD that returns a list of
 > all code points that have a given property.

That is an interesting offer, and I think this should be given serious 
consideration. I'm sure my little module isn't the only one that, as we 
go into the future, would benefit from such a function.

Thanks for your reply, Karl.

Bob